Author Topic: Copper to gas valve  (Read 808 times)

Offline walker

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Copper to gas valve
« on: November 02, 2018, 05:34:30 PM »
Can copper pipe be ran directly to the gas valve, I was under impression that only black pipe can be ran inside the cabinet, couldn't find anything in the code and the installation manual only says that if an appliance connector is used than black pipe must be ran inside the furnace cabinet.

Offline NoDIY

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Re: Copper to gas valve
« Reply #1 on: November 02, 2018, 08:00:29 PM »
most manuals call for a ground joint union. so copper is impractical to use when you need to build a dirt pocket and use a union in black.

Offline Admin

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Re: Copper to gas valve
« Reply #2 on: November 02, 2018, 08:20:53 PM »
I used to see alot of older propane furnaces that used rigid drops and dirt pockets, then used copper to enter the furnace cabinet and gas valve.  It would be coated copper, wrapped or ran through drain tubing where it entered the cabinet.

I know the Gas Code prevents us from using CSST as a gas connector but I don’t know of any Codes that prevent copper from being used.

It would really depend on what the installation manual says.  The Goodman GMEC96 has an open burner box and requires that the furnace cabinet stay sealed.  They only allow rigid piping to pass through the rubber grommet on the furnace casing.

Quote
• Connect the furnace to the building piping by one of the following methods:
– Rigid metallic pipe and fittings.
– Semi-rigid metallic tubing and metallic fittings. Aluminum alloy tubing must not be used in exterior locations. In order to seal the grommet cabinet penetration, rigid pipe must be used to reach the outside of the cabinet. A semi-rigid connector to the gas piping may be used from there.

Lennox uses a sealed burner box in the EL296 model but still only references using rigid piping to enter the cabinet.

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Gas piping may be routed into the unit through either the left or right hand side. Supply piping enters into the gas valve from the side of the valve as shown in figure 54.

I just noticed the OP never mentioned what type of appliance.  With a gas fireplace, if the gas line was under 50 feet, the shut off valve could be installed downstream of the copper.  Then the copper could be connected directly into the gas valve.  Unless of course the manual requires a gas connector or union.


Offline walker

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Re: Copper to gas valve
« Reply #3 on: November 02, 2018, 08:36:24 PM »
most manuals call for a ground joint union. so copper is impractical to use when you need to build a dirt pocket and use a union in black.

This particular furnace did have a union and a dirt pocket, it just used copper off the tee to the gas valve.

Offline walker

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Re: Copper to gas valve
« Reply #4 on: November 02, 2018, 09:16:53 PM »
I just noticed the OP never mentioned what type of appliance.  With a gas fireplace, if the gas line was under 50 feet, the shut off valve could be installed downstream of the copper.  Then the copper could be connected directly into the gas valve.  Unless of course the manual requires a gas connector.

I was speaking of a furnace.

Offline Hvacpimp

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Re: Copper to gas valve
« Reply #5 on: November 02, 2018, 09:49:56 PM »
You definitely cannot have copper go through the cabinet. Has to be black iron. Just went through a training course that brought up this topic. They also said that if a gas connector is used the drop to the furnace has to be supported.

Offline Admin

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Re: Copper to gas valve
« Reply #6 on: November 03, 2018, 06:28:42 AM »
Quote
This particular furnace did have a union and a dirt pocket, it just used copper off the tee to the gas valve.

Unless the manual specifically said to use rigid through the cabinet I don’t see a problem doing this.

I’m just not sure what your manual means by appliance connector.  A gas connector would be factory fabricated, which the copper piece is not.

Offline Porcupinepuffer

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Re: Copper to gas valve
« Reply #7 on: November 03, 2018, 07:07:47 AM »
With a gas fireplace, if the gas line was under 50 feet, the shut off valve could be installed downstream of the copper.  Then the copper could be connected directly into the gas valve.

Just need to watch out with this one. In many instances a fireplace insert can easily have a gas run of less than 10' to connect in the mechanical room below... But the walking distance from the fireplace to that valve needs to be within 50'... In most of those instances, the distance of travel from that valve to the fireplace is easily over 100'.

Offline walker

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Re: Copper to gas valve
« Reply #8 on: November 04, 2018, 08:11:28 AM »
Quote
This particular furnace did have a union and a dirt pocket, it just used copper off the tee to the gas valve.

Unless the manual specifically said to use rigid through the cabinet I don’t see a problem doing this.

I’m just not sure what your manual means by appliance connector.  A gas connector would be factory fabricated, which the copper piece is not.

I believe it meant one of those gas connectors used for stoves and dryers.  But I was also under the impression that those appliance connectors arent meant to only be used on non stationary appliances and unit heaters.

Offline Admin

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Re: Copper to gas valve
« Reply #9 on: November 04, 2018, 09:37:02 AM »
I'm not really sure if we're interpreting Clause 6.21.3(c) properly, and if a normal upflow furnace is considered a free-standing unit.  I think free-standing implies the appliance is not secured.  I don't see a problem using a gas flex connector to connect from the shut-off valve to a dirt pocket, as long as the gas flex connector remained outside of the furnace cabinet.

Quote
Clause 6.21.3 - Except as specified in Clause 7.22.3, a corrugated metal gas connector certified to ANSI Z21.24/CSA 6.10 may be used to connect
(a) a range, refrigerator, clothes dryer, or built-in counter appliance to piping or tubing, provided that the connector length does not exceed 6 ft (2 m);
(b) a suspended appliance to piping or tubing, provided that the gas connector length does not exceed 2 ft (600 mm); or
(c) a decorative appliance, a room heater, or a direct-vent wall furnace to piping or tubing, except when the appliance, heater, or furnace is installed as a free-standing unit, provided that the gas connector length does not exceed 2 ft (600 mm).

Clause 6.21.7 seems to say if our vented appliance is secured (ie: to ductwork) we can use a gas flex connector.  I don't think this Clause only applies to a space heater, it's just giving that as an example.

Quote
Clause 6.21.7 - A gas connector not exceeding 2 ft (600 mm) may be used on a vented appliance, such as a free-standing space heater, provided that the appliance is secured to prevent dislodgement of the vent.

The Lennox EL296 manual says,

Quote
If a flexible gas connector is required or allowed by the authority that has jurisdiction, black iron pipe shall be installed at the gas valve and extend outside the furnace cabinet. The flexible connector can then be added between the black iron pipe and the gas supply line.

The Goodman GMEC96 and GMVC96 manuals says,

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Use listed gas appliance connectors in accordance with their instructions. Connectors must be fully in the same room as the furnace.
• Protect connectors and semirigid tubing against physical and thermal damage when installed.

I’m sure the inspector could force you to provide some sort of protection if you used a gas connector on these Goodman furnaces.  Clause 6.21.2 also says to protect a gas connector.  Would you sleeve it with plastic conduit?  It seems easier to avoid using gas connectors on furnaces.

The attached picture is from the B149 Handbook and shows to use a gas flex connector the appliance must be made unmoveable and, like Hvacpimp said, the drop must be supported.